/*
* Copyright 2008 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
using System;
using BarcodeFormat = com.google.zxing.BarcodeFormat;
using DecodeHintType = com.google.zxing.DecodeHintType;
using ReaderException = com.google.zxing.ReaderException;
using Result = com.google.zxing.Result;
using BitArray = com.google.zxing.common.BitArray;
namespace com.google.zxing.oned
{
    
    /// <summary> <p>A reader that can read all available UPC/EAN formats. If a caller wants to try to
    /// read all such formats, it is most efficient to use this implementation rather than invoke
    /// individual readers.</p>
    /// 
    /// </summary>
    /// <author>  Sean Owen
    /// </author>
    /// <author>www.Redivivus.in (suraj.supekar@redivivus.in) - Ported from ZXING Java Source 
    /// </author>
    public sealed class MultiFormatUPCEANReader:OneDReader
    {
        
        //UPGRADE_NOTE: Final was removed from the declaration of 'readers '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
        private System.Collections.Generic.List <Object> readers;
        
        public MultiFormatUPCEANReader(System.Collections.Generic.Dictionary <Object,Object> hints)
        {
            //System.Collections.Generic.List <Object> possibleFormats null?null:(System.Collections.Generic.List <Object>) hints[DecodeHintType.POSSIBLE_FORMATS];
            System.Collections.Generic.List<Object> possibleFormats = null; //WP7 Port: above was throwing an exception when hints did not include Possible Format key
            if (hints != null && hints.ContainsKey(DecodeHintType.POSSIBLE_FORMATS))
            {
                possibleFormats = (System.Collections.Generic.List <Object>) hints[DecodeHintType.POSSIBLE_FORMATS];
            }
            readers = new System.Collections.Generic.List <Object>(10);
            if (possibleFormats != null)
            {
                if (possibleFormats.Contains(BarcodeFormat.EAN_13))
                {
                    readers.Add(new EAN13Reader());
                }
                else if (possibleFormats.Contains(BarcodeFormat.UPC_A))
                {
                    readers.Add(new UPCAReader());
                }
                if (possibleFormats.Contains(BarcodeFormat.EAN_8))
                {
                    readers.Add(new EAN8Reader());
                }
                if (possibleFormats.Contains(BarcodeFormat.UPC_E))
                {
                    readers.Add(new UPCEReader());
                }
            }
            if ((readers.Count == 0))
            {
                readers.Add(new EAN13Reader());
                // UPC-A is covered by EAN-13
                readers.Add(new EAN8Reader());
                readers.Add(new UPCEReader());
            }
        }
        
        public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Generic.Dictionary <Object,Object> hints)
        {
            // Compute this location once and reuse it on multiple implementations
            int[] startGuardPattern = UPCEANReader.findStartGuardPattern(row);
            int size = readers.Count;
            for (int i = 0; i < size; i++)
            {
                UPCEANReader reader = (UPCEANReader) readers[i];
                Result result;
                try
                {
                    result = reader.decodeRow(rowNumber, row, startGuardPattern, hints);
                }
                catch (ReaderException re)
                {
                    continue;
                }
                // Special case: a 12-digit code encoded in UPC-A is identical to a "0"
                // followed by those 12 digits encoded as EAN-13. Each will recognize such a code,
                // UPC-A as a 12-digit string and EAN-13 as a 13-digit string starting with "0".
                // Individually these are correct and their readers will both read such a code
                // and correctly call it EAN-13, or UPC-A, respectively.
                //
                // In this case, if we've been looking for both types, we'd like to call it
                // a UPC-A code. But for efficiency we only run the EAN-13 decoder to also read
                // UPC-A. So we special case it here, and convert an EAN-13 result to a UPC-A
                // result if appropriate.
                if (result.BarcodeFormat.Equals(BarcodeFormat.EAN_13) && result.Text[0] == '0')
                {
                    return new Result(result.Text.Substring(1), null, result.ResultPoints, BarcodeFormat.UPC_A);
                }
                return result;
            }
            
            throw ReaderException.Instance;
        }
    }
}